Here's some pictures you may find interesting of the rather imposing Pylon on the A628 Manchester-Sheffield road at the head of the old Woodhead rail tunnel - no longer used for rail but instead it carries a couple of 400KV cables:

That's the view you get from the road. A couple of years ago I took the time to get a little closer and take some more detailed pictures:

An interesting post here and good to see this relatively modern structure being put to good use. The tunnel is the new Woodhead Tunnel opened as recently as 1953 and closed less than thirty years later in 1981. From its opening it was associated with electricity â€“ in its earlier days 1500V d.c. traction supply. It was a heavily used route across the Pennines â€“ mainly coal â€“ and identified before the War by the then L.N.E.R. as a prime candidate for electrification. Work started before the hostilities but was halted when war broke out.

The first locomotive built for the electrified route was completed in 1941 but saw no use other than testing until 1947 when it was leant to the Dutch national railways where it gained the name â€˜Tommyâ€™ after the liberating British soldiers.

The original tunnels parallel the one pictured and were smoke filled hell-holes â€“ single track, each on a rising gradient with heavy loads in tow. Their size made them unsuitable for electrification and hence the new bore pictured above. At one time there was a signal box halfway in one of the old tunnels to break the block section â€“ the tunnels are over three miles long. Pity the poor men that had to work that shift!

Declining freight led to the premature closure of the route with its then unique (for the UK) electrical supply. If it had hung on a few more years it would likely have been converted to 25 kV a.c. (like the Manchester commuter end was) and be a valuable part of the national network. Many plans have been muted for its reopening as there are currently serious traffic bottle-necks across the Pennines. If they eventually do reopen it, it will be interesting to see what they do with the 400 kV line that currently occupies the vacant track-bed. Maybe reroute it through one of the old 1850 tunnels.

jusme,What is the "helmet" over the top of the Surge Diverters in Pic 5?.Is this to prevent Corona Discharge with double conductors?.What type Insulators do you guys use at these voltages?, as they seem rather thin.Just my opinion.

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What is the "helmet" over the top of the Surge Diverters in Pic 5?.Is this to prevent Corona Discharge with double conductors?.What type Insulators do you guys use at these voltages?, as they seem rather thin.Just my opinion.

Sorry, I can't help with any details, for me anything over 12V is HT now. I did once have "hands on" some insulator strings in the Uni. HT lab, but that was too long ago :-)

I'd be interested to hear any technical details though too, along with any more information about the tunnel (Thanks Hutch).

It may well be from the information on this site that the power line actually goes through one of the old tunnels, now equiped with a narrow guage railway for man access. It seems like the new Woodhead Tunnel is really ready for the renewal of its electrified rail service.

One of the original locos ...

got from here . There is some additional information here which dates the powerline instalation to the mid-1960s when the new tunnel was still in use by the railway - hence the use of the old tunnel. There is an interesting contemparary photograph here with some informative articles as part of the site. Mention is made of 9" of soot requiring removal before the instalation of the powerline!